Finally I found some time to buy some Arduino and test it. Basically it works. I've got a list of Mav2Duplex sensors in my sensors list where I can choose which ones I want to get displayed.

Most important for me is battery voltage and GPS satfix and both work fine. However, number of satellites doesn't work, it always indicates 255. Also nav height remains at 0.0m but I'm not yet sure if it's the relative height to the ground while flying in any mode or if it only displays height while navigating.

Compared to the Mav2Hott it seems poorly equipped but it offers me all I need. While testing with my Graupner radio, I never used the waypoint editor because editing waypoints with my android tablet is much more comfortable.

Meanwhile I have found some time and added GPS coordinates and HAcc/VAcc.

These Jeti guys are really cool because if there is no telemetry reception anymore (i.e. lost flight battery after a crash), the GPS coordinates remain in the radio display until they get updated by new values. There is no need to log these values because unless you turn off the radio, you always have the last known position of your model.

I obviously need some help. Basically the Arduino code works fine. I've cleaned it up and added some telemetry parameters that I found to be usefull.

The original code was obviously written for APM and my problem now is that the armed status works very slowly and thus is not reliable. All other parameters are from the common mavlink library while the script gets the status from an ardupilot-specific part of the library. Probably this is the reason why it is so slowly.

A fast status update would be nice since it allows to program my radio for things like "automatically turn off audio warnings like battery low voltage warnings after disarming".

After checking the MAVLink librarys I have to admit: I don't know how to include the Autoquad stuff into the MAVLink library that came with the original Arduino code.